:root {
    --primary-color: #4a90e2;
    --background-color: #f0f2f5;
    --text-color: #333;
    --white: #fff;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.container {
    text-align: center;
    background-color: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 12px var(--shadow-color);
}

h1 {
    color: var(--primary-color);
}

#numbers-display {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin: 2rem 0;
}

.number-ball {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--white);
    background-color: var(--primary-color);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

#generate-btn {
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 1rem 2rem;
    font-size: 1rem;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

#generate-btn:hover {
    background-color: #357abd;
}